Metallic materials, metal alloys, and metallic materials, including pure metals, bulk metals, specialty alloys, metallic films and coatings, are formed of a plurality of single crystals, which are often referred to as “grains.” The interfaces or boundaries between individual crystals are referred to as “grain boundaries,” and govern material properties such as mechanical strength, deformation, ductility, and electrical resistivity. These properties are affected by the number of grain boundaries formed, as well as the density and orientation of the grain boundaries. A particular type of boundary referred to as a “twin boundary” or “twin” is a grain boundary that has symmetrical “mirror image” structures. Twin boundaries advantageously preserve favorable qualities of grain boundaries and suppress unfavorable properties such as the initiation of cracks, inclusions, and other unwanted flaws. Twin boundaries are usually more stable than conventional grain boundaries when the material is heated, and usually maintain a relatively high strength at higher temperatures experienced during heating.